Phono pre amp

About 2 weeks ago I posted this question about upgrading the phono stage of my Yamaha AS2100. You guys gave me a lot of ideas, so I did my homework and chose a barely used Musical Fidelity Nu Vista Vinyl. I'm using the XLR output to my Yamaha. I've played with it briefly and It sounds great. My question is, how do I determine which settings to use? Do I choose with my ears? I have a VDH MC DDT II Special cartridge and a VPI Prime TT with the 10" JMW tone arm. Any suggestions would be appreciated.